1. Field of the Invention
The present invention relates to a stereoscopic image display system.
Priority is claimed on Japanese Patent Applications Nos. 2004-271510 and 2004-271511, filed Sep. 17, 2004, the contents of which is incorporated herein by reference.
2. Description of the Related Art
A human recognizes a visible object as a stereoscopic image using his/her brain while combining an image viewed by a right eye and an image viewed by a left eye. Since the right and left eyes view the object from different angles, the image viewed by the right eye and the image viewed by the left eye are slightly different from each other, thereby making it possible to achieve this.
Therefore, allowing a viewer to recognize an image displayed two-dimensionally as a stereoscopic image can be achieved by displaying a parallax image composed of the image viewed by the right eye (right eye image) and the image viewed by the left eye (left eye image), thereby allowing only the right eye image to reach the right eye of the viewer and only the left eye image to reach the left eye of the viewer.
Specifically, a stereoscopic image display system is provided with an image display unit that displays the parallax image, and glasses having a transmission portion for the right eye transmitting only the right eye image of the parallax image and a transmission portion for the left eye transmitting only the left eye image of the parallax image while not transmitting the right eye image, wherein the viewer recognizes the stereoscopic image by wearing the glasses. The glasses generally utilize circular polarizing glasses that transmit circularly polarized light with different rotation angles for the transmission portions for the right eye and the left eye, or liquid crystal shutter glasses where the states of the transmission portions for the right eye and the left eye are changed between a transmitting mode and a non-transmitting mode alternately. When the circular polarizing glasses are used, the right eye image of the parallax image is circularly polarized light with a rotation angle that allows the image to be transmitted through the transmission portion for the right eye, while the left eye image of parallax image is circularly polarized light with a rotation angle that allows the image to be transmitted through the transmission portion for the left eye, thereby allowing only the right eye image to reach the right eye of the viewer and only the left eye image to reach the left eye of the viewer. When the liquid crystal shutter glasses are used, the right eye image of the parallax image is displayed when the transmission portion for the right eye is in the transmitting mode and the transmission portion for the left eye is in the non-transmitting mode, while the left eye image of the parallax image is displayed when the transmission portion for the right eye is in the non-transmitting mode and the transmission portion for the left eye is in the transmitting mode, thereby allowing only the right eye image to reach the right eye of the viewer and only the left eye image to reach the left eye of the viewer.
Some of the stereoscopic image display systems provided with such glasses are configured to allow the object viewed from an arbitrary angle by displaying the parallax image in accordance with the free movement of the viewer (refer to Japanese Unexamined Patent Application, First Publication No. 2004-12626).
Specifically, the position of the viewer is detected by detecting the position of the glasses, and the parallax image is displayed based on the detection result.
However, in a conventional stereoscopic image display system, only the position of the glasses is detected while not considering the inclination of the glasses. That is, when the inclination of the glasses is changed at the same position, the parallax image of the stereoscopic image display system is still the same as that displayed before the inclination of the glasses is changed. For example, when the viewer tilts his head for viewing an object displayed by a certain stereoscopic image display system from beneath, the inclination component of the glasses is not recognized by the stereoscopic image display system, thereby making the viewer unable to view the object from the desired angle, bringing about viewer discomfort.
Moreover, because the image display unit displays the right eye image and the left eye image, both the right eye image and the left eye image reach both eyes of the viewer when the viewer takes the glasses off, so that the viewer sees a double image displayed on the image display unit. Therefore, when the viewer has desired to view the displayed object as a two-dimensional (2D) image, it has been impossible to fulfill this need.
Although some of the stereoscopic image display systems are provided with an image display apparatus having an operation unit to switch over between three-dimensional (3D) display and 2D display, such stereoscopic image display systems require the viewer to switch over between the 3D display and the 2D display, and thereby the viewer feels this as burdensome.